We propose the PAA-PEG interpolymer complex as a passivation agent for low dishing with high selectivity between SiO₂ and Si₃N₄.

PAA can form the interpolymer complex with PEG through the H-bonding.

During the over-polishing step, the cross-linked network structure of the PAA-PEG interpolymer complex prevents abrasives from polishing SiO₂ in the trenches, resulting in a significant decrease in dishing.